/*
 * @Author: funlee
 * @Email: i@funlee.cn
 * @Date: 2018-01-12 01:14:06
 * @Last Modified time: 2018-01-12 01:14:06
 * @Description: 二次贝塞尔曲线 
 *   quadraticCurveTo(cx,cy,x2,y2)
 *   (cx,cy)控制点 (x2,y2)结束点
 *   一般由moveTo()或者lineTo() 提供开始点
 */
window.onload = function () {
  var canvas = document.querySelector('.canvas')
  var cxt = canvas.getContext('2d')

  cxt.moveTo(30, 120)
  cxt.quadraticCurveTo(100, 20, 160, 120)
  cxt.stroke()

}
